Endodontic ozone therapy

ABSTRACT

A method for treating root canals includes directing an oxidizing gas onto an open root canal through a needle, maintain a presence of the oxidizing gas onto the root canal for a period of time sufficient to kill microorganisms therein, and preventing escape of the oxidizing gas from the root canal. Apparatus for a treatment of root canals includes a source of oxidizing gas, a handpiece, a needle extending from said handpiece and receivable in a tooth root canal. The needle includes an oxidizing gas delivery lumen therethrough, and a cup is attached to the handpiece and surrounding the needle.

The present application is a continuation-in-part of U.S. Ser. No.11/087,452 filed Mar. 23, 2005, now abandoned which is a continuation ofU.S. Ser. No. 10/097,758 filed Mar. 13, 2002, now U.S. Pat. No.6,875,018 claiming the benefit of U.S. Ser. No. 60/279,360 filed Mar.28, 2001. All of these applications/patent are to be incorporated hereinin this entirety including all specifications and drawings.

This invention relates to the use of ozone in the treatment of dentaland oral conditions.

In order to treat a tooth that has diseased pulp material therein, it isnecessary to remove the diseased pulp material from the pulp cavity, orroot canal to prevent bacterial proliferation within the pulp canal ofthe tooth.

Subsequent to removal of diseased pulp material, the root canal istypically filled with an inert material before sealing off with anaseptic material to prevent continued or future infection of the toothroot.

It is apparent that during root canal therapy the entire root canalincluding the root tip, be cleaned and filled to eliminate all diseasedmaterial.

Typically, this includes opening the tooth to the pulp chamber and thenmanually cleaning the root canal with appropriate instruments.

Access to the pulp chamber is accomplished by drilling a hole throughthe tooth, which is subsequently widened for the use of endodonticinstruments to large and clean the root canal to remove all the diseasedpulp tissue.

Following removal, the root canal must be disinfected and dried prior tofilling. A number of endodontic irrigating instruments are utilized andtypically purge the root canal with a hydrogen peroxide solution or asodium hypochloride solution.

Care in this procedure must be taken in order that the irrigatingsyringe is not inserted too deeply into the root canal or the pressureof the irrigating solutions to prevent flow into the apical dentalformen and into the periapical area.

A further disadvantage of such irrigation is that a saliva remover mustbe inserted into or hanging from the mouth to extract the usedirrigating solutions. This, in turn, may give discomfort to the patientand interfere with the dentist's work.

The present invention provides for disinfecting root canals through theuse of ozone. Such treatment is preferred following pulp removal.

SUMMARY OF THE INVENTION

A method in accordance with the present invention for treating rootcanals includes directing an oxygen gas onto an open root canal througha needle, maintaining a pressure of the oxidizing gas into the rootcanal for a period of time sufficient to kill micro organisms therein,and preventing escape from the oxidizing gas from the root canal.

In addition, a method in accordance with the present invention mayinclude flushing the oxidizing gas from the root canal with a reductant.

Apparatus for the hereinabove treatment of root canals generallyincludes a source of oxidizing gas, a handpiece, a needle extending fromthe handpiece and receivable in a tooth root canal with the needleincluding an oxidizing gas delivering a lumen therethrough. A cup isprovided and attached to the handpiece which surrounds the needle.Preferably, the oxidizing gas comprises ozone. In order facilitate entryof the needle into the root canal, the needle may be flexible.

Preferably, the cup includes a resilient edge engageable with a cusparea of the tooth and the source of oxidizing gas includes an ozonepump.

The apparatus may further include an aspiration pump and an aspirationline connected to the handpiece for circulating the gas through theneedle lumen and out of a cup chamber subtending a cup edge.

The apparatus in accordance with the present invention may furtherinclude an ozone and aspiration pump controller to circulate the gasthrough the needle lumen and out of the cup chamber any pressureinsufficient to escape past a sealed engagement between the cup and thetooth.

The apparatus may further include a source of reductant interconnectedwith the handpiece in order to flush the gas from the cup. In addition,the waste reductant accumulator may be provided to connect to theaspiration line along with a residual oxidizing gas aspiration linefilter.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will be betterunderstood by the following description when considered in conjunctionof the accompanying drawings, in which:

FIG. 1 illustrates a block diagram of apparatus for treatment of rootcanals in accordance with the present invention, the apparatus generallyincluding a source of oxidizing gas, an aspiration pump, a source ofreductant, a reductant pump and a controller for providing the oxidizinggas to a handpiece;

FIG. 2 illustrated an embodiment of handpiece in accordance with thepresent invention for delivering a gas to a tooth and generally showinga cup attached to the handpiece for receiving the gas;

FIG. 3 illustrated the handpiece with an alternative cup embodiment, thealternative embodiment cup having an arcuate shape for facilitatingapplication of oxidizing gas to a tooth;

FIG. 4 is a diagram showing application of oxidizing gas to a toothbetween a cusp and a gingival utilizing the handpiece and cup shown inFIG. 3;

FIG. 5 is cross-sectional view of the cup shown in FIG. 2 that issuitable for use in the present invention;

FIG. 6 is a cross sectional view an alternative embodiment of a cup forexposing a selected area of a tooth oxidizing gas;

FIG. 7 is a cross sectional diagram showing an alternative embodiment ofa cup in accordance with the present invention for exposing adjacentteeth to oxidizing gas;

FIG. 8 illustrates the use of the cup shown in FIG. 7 as it may beapplied to adjacent teeth;

FIG. 9 is a perspective view of an alternative embodiment of the presentinvention showing a handpiece with a needle for injecting an oxidizinggas into a root canal through an oxidizing gas delivery lumentherethrough along with a surrounding cup;

FIG. 10 is a cross sectional view of the handpiece shown in FIG. 9 withthe needle entering a root canal of a tooth; and

FIG. 11 is a view similar to FIG. 10 with the cup engaging a crown/cuspof a tooth to prevent escape of the oxidizing gas and to enablesubsequent evacuation thereof.

DETAILED DESCRIPTION

With reference to FIGS. 1-4, there is shown apparatus 10 in accordancewith the present invention for the treatment of root canals and dentalcaries which includes a source 12 of oxidizing gas, preferably ozone,and a handpiece 16 (see FIG. 2) for delivering the gas to a tooth, notshown in FIGS. 1-3. The effectiveness of an oxidizing gas such as ozoneis set forth in U.S. Pat. No. 6,409,508 entitled “Use Of Ozone For ThePreparation Of Medicaments For The Treatment of Dental Caries” by EdwardLynch. This patent is incorporated herewith in its entirety includingall specification and drawings by this specific reference thereto.

As illustrated in FIG. 1, the ozone source 12 includes an ozonegenerator 20 and an ozone pump 22 for supplying ozone through a line 24,a connector 28 and lines 30 to the handpiece 16. As used herein, theterm “ozone” is intended to embrace any suitable oxidizing gas, pureozone, ionized air and other ozone gaseous mixtures.

As noted in the referenced international patent application, ozone isdelivered at a pressure, concentration and for a period of timesufficient to penetrate the carious tissue and kill substantial all ofthe microorganism within a carious lesion. Specific examples of the useof ozone are set forth in the referenced patent application and areincorporated herewith by the specific reference thereto.

As shown in FIGS. 2-3, cups 34 36 attached to the handpiece 16 areprovided for receiving the gas and exposing a selected area 38 on atooth 40, see FIG. 3. The cup 34 may be attached to the handpiece 16 inany conventional manner and include a resilient edge, or sidewall, 44for sealable engaging the tooth 40 to prevent the escape of gastherepast.

Many different sized and shaped cups may be utilized, as for exampleshown in FIG. 3 the cup 36 includes an arcuate trunk 50 to facilitatethe placement of the cup 36 over the selected area 38 as shown in FIG.4. The cups 34, 36 may have relatively uniform perimeters 52, 54 forsealably engaging the tooth 40 between a cusp 58 and a gingiva 60 asshown in FIG. 4.

A further cup embodiment 64 is shown in cross-section in FIG. 6 includesa tapered sidewall 66 that may be used for application of oxidizing gasto a smaller selected area (not shown) on the tooth 40.

While a resilient edge or sidewall may be used to couple the cup to theselected area 38 on the tooth 40, it should be appreciated that aseparate sealant 68 (See FIG. 6) may be utilized for providing asealable engagement between the cup 64 and the tooth 40. In thisinstance, the sidewall 66 need not be resilient.

Another embodiment of a cup 70 is shown in cross-section in FIG. 7 whichincludes walls 72 which are contoured for enabling the sealableengagement with adjacent teeth 74, 76 as shown in FIG. 8. As shown inFIG. 8, a cup edge 80 has a perimeter contour 82 for providing asealable engagement with cups 86, 88 of adjacent teeth 74, 76.

All of the cups 34, 64, 70, cross-sectionally illustrated in FIGS. 5-7.include cup chambers 92, 94, 96 that subtend cup edges 98, 100, 102. Asshown each of the cups 34, 64, 70 include walls 44, 66, 72 that definethe chambers 92, 94, 96 and include first perimeters 106, 108, 110 forsealably coupling the walls 44,66, 72 to the handpiece 16. Secondperimeters 112, 114, 116 provide for coupling the walls 44,66 72 to thetooth 40 and exposing the selected areas 38 to gas circulated in thechambers 92, 94, 96.

As shown in FIG. 6, the embodiment 64 the first perimeter 108 may belarger than the second perimeter 115 or, as shown in FIG. 7, the firstperimeter 110 may be smaller than the second perimeter 116. Accordinglythis variation in cup 64, 70 design enables the application of oxidizinggas the any number of tooth contours and to the application of oxidizinggas to a plurality of teeth has hereinabove described.

As shown in FIGS. 9-11, there is shown a handpiece 11 having a needle 13extending therefrom and sized for being receivable in a root canal 15 ofa tooth 19 with the needle 13 having an oxidizing gas delivery lumen 23therethrough. A cup 27 attached to the handpiece 11 surrounds the needle13 forms a chamber 31. The needle may be flexible such as, for example,set forth in U.S. Pat. No. 6,638,064.

Following the removal of diseased pulp, the oxidizing gas is directedinto the root canal 15 through the needle 13. The presence of oxidizinggas in the root canal is provided for a period of time sufficient tokill the microorganisms therein. The cup 27 prevents escape of theoxidizing gas from the root canal 15. A seal 35 may be provided to sealacross a tooth crown 27. A single line 39 connected to the needle lumen33 may be provided for both introducing ozone and reductant to the rootcanal 15, or alternating a separate aspiration line 41 may be provided.

In addition, as hereinafter discussed in greater detail, the oxidizinggas may be flushed from the root canal 15 with a reductant.

With reference again to FIG. 1, the apparatus 12 includes an aspirationpump 120 and lines 30, 122, 124 connected to the handpiece 16 forenabling circulation of the ozone into and out of the cup chambers 92,94, 96, or alternatively through the lumen 23 and out of the cup chamber31 (FIGS. 9-11).

A controller 126, which may be of any conventional circuit design, isprovided for regulating the ozone and aspiration pumps 22, 120 in orderto circulate the gas into and out of the cup chambers 92, 94, 96 at apressure insufficient to permit escape of the gas past a sealedengagement between the cup 31 and teeth 40, 86, 88.

The gas may be circulated through the lumen 23 and out of the cupchamber 31 at a pressure insufficient to permit escape of the gas past aneeded engagement between the cup 27 and the tooth 19. Control of thegas flows may also be effected through valves 127, 127 regulated by thecontroller 126.

Additionally, the apparatus 10 may include a reductant source 128, whichis in fluid communication with the cup chambers 31, 92, 94, 96 throughlines 30, 130 and a parastalic pump 131. The reductant, which may be asolution of thiocyanate or peppermint, is utilized to flush the cupchambers 31, 92, 94, 96 of oxidizing gas. The oxidizing gas is flushedinto the aspiration line 122 following ozone treatment of the tooth 19,40, 86, 88. The reductant is then aspirated through line 122 and into awaste accumulator 132.

Any residual ozone is then aspirated from the accumulator 132 throughthe line 124 and into a canister 134 through line 136 for finalelimination of the ozone. Thus, the apparatus 12 provides for a totallyclosed system for the application and removal of ozone to and from teeth19, 40, 86, 88.

It should also be appreciate that when the cups 34, 36, 64 are utilizedbetween teeth 40, 138 (not shown in FIG. 4) a separate dam 140 maybeutilized as necessary to enable the cups 34, 36, 64 (not shown in FIG.4) to sealably enclose a selected area for treatment between the teeth40, 138.

EXAMPLE 1

Many studies concerning the clinical evaluation of ozone have been basedon assessments of its harmful effects rather than demonstrating anytherapeutic benefits it may offer. Ozone is one of nature's mostpowerful oxidants which accounts for its ability to kill bacteria,spores and viruses. Uniquely, ozone decomposes to a harmless, non-toxicand environmentally safe material (oxygen). In this investigation, amulticomponent evaluation of the oxidative consumption of salivarybiomolecules by ozone (O₃) has been performed using high resolutionproton (¹H) nuclear magnetic resonance (NMR) spectroscopy. Theozone-generating equipment employed in this study was designed byPurezone Ltd. (Ipswich, U.K.). Unstimulated human saliva samples werecollected from 8 patients and each of them was divided into twoequivalent portions (0.60 ml). The first of these was treated with O₃generated from the above device for a period of 30 seconds; the secondgroup of portions served as controls. Samples were subjected to ¹H NMRanalysis at an operating frequency of 600 MHz. Results acquired revealedthat O₃ treatment gave rise to (1) the oxidative decarboxylation of thesalivary electron-donor pyruvate (generating acetate and CO₂, asproducts), (2) oxidation of the volatile sulphur compound precursormethionine to its corresponding sulphoxide and (3) the oxidativeconsumption of salivary polyunsaturated fatty acids. Moreover, evidencefor the O₃-mediated oxidation of salivary 3-D-hydroxybutyrate was alsoobtained. High field ¹H NMR spectroscopy provides much useful analyticaldata regarding the fate of O₃ in human saliva, information which is ofmuch relevance to its potential therapeutic actions in vivo.

EXAMPLE 2

Ozone Effect on Microflora from Primary Root Caries Ex-Vivo

Primary root carious lesions (PRCL) are a major clinical problem. Theaim of this study was to establish if ozone could achieve effectivemicrobial killing in PRCL. An ozone producing generator (Purezone Ltd.,Ipswich, U.K.) was used in this ex-vivo study assessing the use of ozoneon PRCL. In this study, soft PRCL requiring restoration were used asthese are the most severe type of lesion found in humans. 20 freshlyextracted teeth with PRCL requiring restoration were used. After plaqueremoval using a hand held standard fine nylon fiber sterile toothbrushwith sterile water as a lubricant to cleanse the surface, each tooth wasthen isolated using sterile cotton wool rolls and dried using a drysterile cotton wool roll. A sample of PRCL was taken using a sterileexcavator from half of the most active part of the lesion. Subsequently,10 seconds of the ozonized water was applied to the lesion and anothersample was taken from the other half of the most active part of thelesion. Each sample was weighed and immediately placed in 1 ml ofFastidious Anaerobe Broth (FAB). To each 1 ml of FAB containing a biopsyo carious or ozone treated carious dentine, sterile glass beads wereadded. They were vortexed for 30 seconds to facilitate the extraction ofany micro-organisms from the carious dentine and disperse anyaggregates. After decimal dilution with FAB, 100 ml aliquots of thesewas spread on Fastidious Anaerobe Agar (LabM, Bury, Lancs., U.K.)supplemented with 5% (v/V) horse blood in an anaerobic chamber at 37° C.for four days. The mean±SE number of each colony type was counted andcalculated.

Before Ozone After 10 Seconds Treatment of Ozone Treatment Mean ± SE of5.9 ± 0.15 3.57 ± 0.37 Total cfu (Log₁₀)

Using the paired Student t-test a significant difference (p<0.001) wasobserved between the two groups. Clearly, the percentage ofmicro-organisms killed associated with the use of ozone was more than99%.

EXAMPLE 3

Ozone Effect on Microflora from Primary Root Caries Ex-Vivo

The procedure of Example 2 was repeated except that ozonized water wasapplied to the lesion for 20 seconds. Using the paired student t-test, asignificant difference was observed in the ozonized water group (log₁₀3.77±0.42, mean±SE) compared with the control group (log₁₀ 6.18±0.21)(p<0.001).

The results of these tests show that the use of ozone can provide aneffective, rapid and simple means for killing micro-organisms in cariouslesions.

EXAMPLE 4

Sealant Shear Bond Strength to Sound and Carious Radicular Dentine

These has been little research on the interaction between primary rootcarious lesions (PRCL) and adhesive materials. The aim of this study wasto examine the shear bond strength of four adhesive systems to PRCL withsound dentine acting as a control. The adhesive systems used were:

-   1. OptiBond FL Prime¹/OptiBond FL Adhesive¹/OptiGuard¹-   2. OptiBond FL Prime/OptiGuard-   3. OptiGuard and-   4. ChemFil II² ¹Kerr, Romulus, Mich., U.S.A.;²Dentsply, Konstanz,    Germany.

The materials were applied to sound radicular dentine and PRCL in vitroin freshly extracted teeth. The bonding site was macroscopically intact,was flat and had at least a 3.5 mm diameter. 37% phosphoric acid wasused for 15 seconds in samples in groups 1->3 whilst 25% polyacrylicacid was used in group 4. After bonding the samples were stored forseven days in a moist atmosphere at 37° C. A shearing force was appliedat 1 mm/minute. There were at least 10 samples in each group. The mean(s.e.) shear bond strengths were (MPa);

Adhesive Control Carious OptiBond FL Prime/Optibond 5.31 (1.03) 5.58(1.05) FL Adhesive/OptiGuard Optibond FL Prime/OptiGuard 2.01 (0.59)1.63 (0.40) OptiGuard 0.73 (0.24) 1.45 (0.52) ChemFil II 1.42 (0.28)1.01 (0.26)

While statistical testing showed that the shear bond strength of theOptiBond FL Prime/OptiBond FL Adhesive/OptiGuard was significantly thehighest, (p<0.001), the caries status of the root surface had nosignificant influence on the bond strength. OptiGuard in combinationwith OptiBond FL Prime and OptiBond Adhesive had the highest bondstrength and this was not influenced by the caries status of thesurface.

EXAMPLE 5

The Effect of Ozone on Primary Root Caries and AssociatedMicro-organisms

The aims of these studies were to evaluate the efficiency of ozone onprimary root caries and associated micro-organisms (Streptococcussobrinus; TH 21 Streptococcus mutans; NCTC 10449). In study 1, 40 softprimary root carious lesions (PRCLs) from freshly extracted teeth wereused and randomly divided into two groups to test the exposure to ozonefor either 10 or 20 seconds. There was a significant (p<0.001)difference (Mean±SE) between the control samples for either 10 seconds(log₁₀ 5.91±0.15) or 20 seconds (log₁₀ 6.18±0.21) and ozone treatedsamples for either 10 seconds (log₁₀ 3.57±0.37) or 20 seconds (log₁₀3.77±0.42). In study 2, 40 sterile saliva coated glass beads were putinto bijoux bottles with 3 mls of Todd Hewitt broth for control and testgroups. S. sobrinus and S. mutans were inoculated and incubatedanaerobically overnight. Each glass bead was washed with 2 mls of PBS.Immediately, 10 seconds of ozone was applied to the glass beads in thetest groups. Subsequently, each glass bead in the test and controlgroups was placed in 3 mls of Todd Hewitt broth with six more sterileglass beads and were vortexed for 30 seconds. After decimal dilutions,100 ml aliquots were spread on blood agar plates supplemented with 5%(V/V) horse blood and placed in an anaerobic chamber at 37° C. for twodays. The number of each colony type was counted and calculated. Usingthe paired student t-test, there was a significant reduction (p<0.0001)(Mean±SE) between the control samples for S. sobrinus (log₁₀ 4.61±0.13)and S. mutans (log₁₀ 3.93±0.07) and ozone treated samples for S.sobrinus (log₁₀ 1.09±0.36). This treatment regime is therefore aneffective, quick, conservative and simple method to kill micro-organismsin primary root carious lesions.

EXAMPLE 6

The Effect of Ozone on Gum Disease

Inflamed human gingivitis is exposed to ozone using the techniquesherein described. After exposure to ozone, the inflammation isilluminated or reduced. In addition, enzyme levels in extracts frominflamed human gingiva are alleviated and/or reduced.

EXAMPLE 7

The Effect of Ozone on the Treatment of Root Canals

Bacteria cultures of Streptococcus aurous, Lactobacillus salivarius andLactobacillus acidophilus, known as being associated with dentaldiseases are exposed to ozone using the techniques herein described andgrowth of the bacteria cultures is eliminated or inhibited.

EXAMPLE 8

The Effect of Ozone in the Treatment of Month Ulcerations

Month ulcerations are exposed to ozone using the techniques hereindescribed and microorganisms in the ulceration are eliminated orreduced. In addition, enzyme levels in the month ulcerations arealleviated and/or reduced.

EXAMPLE 9

The Effect of Ozone in the Treatment of Bad Breath

Bad breath is caused, in part, by the retention and subsequentdegradation of dead cellular material, by microorganisms, sloughed offcontinuously by a normal, healthy mouth. A mouth is exposed to ozoneusing the techniques herein described and the microorganisms associatedwith bad breath are eliminated or reduced. In addition enzyme levels inthe month are alleviated and/or reduced.

The present invention further relates to apparatus for the treatment ofdental caries utilizing an oxidizing gas.

The role of specific micro-organism such as, for example, streptococcusmutants in dental caries is well documented. Enzymes produced by suchmicro-organisms synthesize dextran from the sucrose passing through themonth with food or drink resulting in the formation of dental plaque anddental caries.

Dental caries is the decay of teeth caused by demineralization of theenamel surface with organic acids produced by bacteria which adhere toteeth surfaces.

Heretofore, dental caries have been removed through the use ofconventional grinding handpieces, lasers and air-blasting apparatus.However high-speed turbine drills or low-speed drills unfortunately willgrind both caries and sound dentine. Accordingly, a practitioner mustselect and grind only caries and consequently, this method depends uponthis skill of the practitioner. Lasers have been utilized to removecaries, however, not much success has been achieved for varies reasons.For example, blackened charred tissue blocks the laser radiation which,in turn, prevents the laser from reaching caries therebelow. Inaddition, heating also interrupts the ablation process.

With regard to air-blasting treatment of caries sound, dentine may alsobe easily removed, and accordingly, the skill of the practitioner is ofoutmost importance.

The present invention provides for the treatment of caries without thedisadvantages of the prior art hereinabove noted.

EXAMPLE 10 Ozone Detection (ppm) Around the Cup Using a Ozone AnalyzerAfter Either 10 or 20 s of Ozone Application in Vivo

Study or Test: Ozone Detection (ppm) Around the Cup 34 Using a OzoneAnalyzer after Either 10 or 20 s of Ozone Application In Vivo

Purpose: To assess the maximum ozone detectable level (ppm) around thecup 34 after either 10 s or 20 s of ozone application in vivo.

Study or Test Protocol: 20 primary root carious lesions (PRCLs) wererandomly selected when the cross-sectional study was conducted. The tipof the sensor was always held within 2 mm of the edge of the cup,positioned half way between the mesial and occlusal sides of the cup.The maximum ozone detectable level (ppm) around the cup from theextracted teeth using an ozone analyzer after 10 s of ozone application.The ozone analyzer used was an API 450 model available from ENVIROTechnologies, UK, and was calibrated by the supplier within the previousweek of delivery and this device was not used for any other purposeother than this study in the interim.

Overlying plaque was then removed using a hand held standard fine nylonfiber sterile toothbrush with water as a lubricant. Each tooth was driedusing dry sterile cotton wool rolls and a dental 3 in 1-air syringe. Theexcavator blade was used to traverse the lesion in line with long axisof the tooth across the maximum gingival/occlusal dimension. Half ofeach lesion was removed using a sterile excavator. Subsequently, theremaining lesion was exposed to the ozone gas for a period of either 10s or 20 s at room temperature (23° C.) and maximum detectable ozonelevel was also measured using this ozone analyzer.

Test Results:

The maximum ozone detectable level (ppm) around the cup from lesions fora period of either 10 s (Table 1 and FIG. 1) or 20 s (Table 2 and FIG.2) ozone application during the treatment of root carious lesions wereas follows:

TABLE 1 Maximum ozone detectable level (ppm) after a 10 s of ozoneapplication Ozone detection Teeth types Sites (10 s) Upper left incisorMesial 0.066 Upper right 1. premolar Buccal 0.001 Upper right canineDistal 0.002 Upper right 1. molar Buccal 0.006 Upper left 2. premolarBuccal 0.076 Lower right 2. premolar Mesial 0.058 Lower left 1. premolarBuccal 0.169 Lower left lateral Buccal 0.106 Upper right lateral Distal0.001 Lower left canine Labial 0.147

TABLE 2 Maximum ozone detectable level (ppm) after a 20 s of ozoneapplication Ozone detection Teeth types Sites (20 s) Lower left lateralLabial 0.137 Lower left 1. premolar Buccal 0.177 Lower right incisorLabial 0.069 Upper right canine Labial 0.033 Upper right lateral Labial0.079 Lower left 2. premolar Buccal 0.002 Lower right1. molar Buccal0.083 Upper left lateral Labial 0.004 Lower left canine Labial 0.056Upper left 1. premolar Mesial 0.001

Conclusion: The use of a cup is a safe way of delivering ozone whenozone was applied for a period of either 10 s or 20 s on the rootcarious lesions.

EXAMPLE 11 Assessment of Maximum Ozone Levels from Extracted Teeth afterthe Use of Ozone for 10 s.—An in Vitro Test Report

Study or Test: Assessment of the maximum detectable ozone levels,detected adjacent to the cup, from extracted teeth after the use ofozone for 10 s in vitro.

Purpose: To assess the maximum ozone detectable level (ppm) around a cupfrom the extracted teeth after a 10 s application of ozone.

Study or Test Protocol: 14 extracted teeth were selected. The tip of thesensor was always held within 2 mm of the edge of the cup, positionedhalf way between the mesial and occlusal sides of the cup. The maximumozone detectable level (ppm) around the cup from the extracted teethusing an ozone analyzer was recorded during 10 s of ozone applicationwith the generator setting on maximum at level 10. The ozone analyzerused was the API 450 model and this was calibrated by the supplierwithin the previous week of delivery. This device was not used for anyother purpose other than this study in the interim.

The Ozone Delivery System

After plaque removal with 2 sterile cotton wool rolls, ozone gas wasdelivered onto the surface of each primary root carious lesion in eachextracted tooth for 10 s after the lesion was dried for three secondswith a standard three in one dental syringe.

Test Results:

The maximum ozone detectable level (ppm) around the cup from theextracted teeth after a 10 s application of ozone during the treatmentof root carious lesions were as shown in Table 3.

TABLE 3 Maximum ozone detectable level (ppm) Teeth types Sites Ozonedetection Upper incisor Mesial 0.005 Upper lateral incisor Labial 0.004Upper canine Labial 0.003 Upper 1. premolar Mesial 0.006 Upper 2.premolar Distal 0.002 Upper 1. molar Buccal 0.003 Upper 2. molar Mesial0 Lower incisor Lingual 0.007 Lower lateral incisor Distal 0.001 Lowercanine Mesial 0 Lower 1. premolar Distal 0.009 Lower 2. premolar Lingual0.018 Lower 1. molar Lingual 0.016 Lower 2. molar Mesial 0.005Conclusion: The use of a cup is a safe way of delivering ozone whenozone was applied for a period of 10 s on the root carious lesions onextracted teeth.

EXAMPLE 12 Measurement of Ozone from the Handpiece

The handpiece 16 from the ozone generator 20 was attached directly tothe inlet pipe a Mini-HiCon™ the ozone detector (not shown).

Peak readings from Mini-HiCon™ (g/Nm³)

Duration Reading 1 Reading 2 Reading 3 Reading 4 Reading 5 Reading 6Average (seconds) (g/Nm³) (g/Nm³) (g/Nm³) (g/Nm³) (g/Nm³) (g/Nm³)(g/Nm³) 5 5.4 5.3 5.4 4.3 5.2 5.2 5.1 10 4.7 4.8 4.6 3.5 4.4 4.5 4.4 204.9 5.9 6.3 6.3 5.9 30 6.3 6.5 6.3 6.6 6.4 60 6.6 7.0 7.0 6.7 6.8Peak readings from Mini-HiCon™ (ppm)

Duration Reading 1 Reading 2 Reading 3 Reading 4 Reading 5 Reading 6Average (seconds) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) 5 2522 24752522 2008 2428 2428 2397 10 2195 2242 2148 1635 2055 2102 2063 20 22882755 2942 2942 2732 30 2942 3036 2942 3082 3000 60 3082 3269 3269 31293187The peak reading was obtained after about 8 seconds (even when thegenerator was switched on for only 5 seconds) and perhaps represented an“overshoot” before the generator/detector combination stabilized forthe >20 second durations. The level then remained fairly constant atbetween 3.6 and 4.7 g/Nm³.To Convert from g/m³ to ppm:The formula weight of ozone is 48 g and therefore 1 g of ozone is 1/48thof a mole.The molar volume of an ideal gas (at standard temperature and pressure)is 0.0224138 m³/mol.0.0224138/48=467×10⁻⁶ m³.Therefore 1 g/m³ of ozone in air is 467 ppm.(The ozone detector gives readings as g/Nm³ which is “normalized” tostandard temperature and pressure).Measurement of the Ozone Dissolving in a Potassium Iodide SolutionOzone was passed through the handpiece 16, immersed in 100 ml of a 20 mMpotassium iodide solution in a 250 ml conical flask covered withparafilm for the stated durations. The handpiece was then removed andthe flask sealed with a neoprene bung and shaken vigorously. A 1.50 mlaliquot was removed and its electronic absorption spectrum acquired.(These measurements were taken before a diffuser was fitted.) Thegenerator settings were:—air=1, O₃=1, vac=0, red=0,regulator-setting=10.

λ_(max) λ_(max) λ_(max) λ_(max) (351 nm) Duration (351 nm) (351 nm) (351nm) average (seconds) absorbance absorbance absorbance absorbance 1 0.060.08 0.11 0.08 2 0.50 0.44 0.26 0.40 3 0.70 0.56 0.42 0.56 4 0.77 0.690.50 0.65 5 0.90 0.84 0.51 0.75 6 1.08 0.99 0.68 0.92 7 1.17 1.11 0.751.01 8 1.30 1.27 0.95 1.17 9 1.40 1.40 1.19 1.33 10  1.57 1.43 1.38 1.46To calculate the Concentration from the Peak Absorbance:

A = E × C × L where L = cell path length (1 cm) C = concentration (mol)E = extinction coefficient A = absorbance E for 1 M = 2.97 × 10⁴ E for 1μM = 0.0297 C = A ÷ E

concentration in μmol/l is absorbance/0.0297

Total Volume of λ_(max) dissolved air/ozone Ozone Ozone Durationabsorbance Concentration ozone Ozone mixture in air in air (seconds)(average of 3) (μmol/l) (μmol) (μg) (ml) (μg/ml = g/m³) (ppm) 1 0.082.69 0.269 13 8 1.625 759 2 0.40 13.47 1.347 65 16 4.063 1897 3 0.5018.86 1.886 91 24 3.792 1771 4 0.65 21.89 2.189 105 32 3.281 1532 5 0.7525.25 2.525 121 40 3.025 1413 6 0.92 30.98 3.098 149 48 3.104 1450 71.01 34.39 3.439 165 56 2.946 1376 8 1.17 39.39 3.939 189 64 2.953 13799 1.33 44.79 4.479 215 72 2.986 1394 10 1.46 49.16 4.916 236 80 2.9501378NMR Analysis of Plaque/Caries

-   1. Plaque samples were obtained from volunteers and each sample was    divided into two. Half of each sample was treated with ozone and    half left untreated as a control.-   2. The samples were each weighed. Then 600 μl of 0.5 M HClO₄ was    added to each sample and rotamixed.-   3. The samples were centrifuged and supernatants retained.-   4. The samples were neutralized to a pH of between 6 and 8 and the    volume of KOH used was noted.-   5. The samples were centrifuged again and 600 μl of supernatant were    taken for analysis.-   6. 70 μl of D₂O and 30 μl of sodium    3-trimethylsilyl-(2,2,3,3,-²H₄)-propionate

(5 mM in D₂O) were added prior to NMR analysis.

NMR Analysis of Saliva

-   1. Saliva samples were obtained from volunteers and each sample was    divided into two. Half of each sample was treated with ozone and    half left untreated as a control.-   2. The samples were centrifuged and supernatants retained.-   3. 70 μl of D₂O and 30 μl of sodium    3-trimethylsilyl-(2,2,3,3,-²H₄)-propionate

(5 mM in D₂O) were added prior to NMR analysis.

Iodine Standards (in 20 mM Potassium Iodide)

Iodine Concentration Absorbance at 351 nm 4 uM 0.1144 5 uM 0.1410 7 uM0.1690 10 uM  0.2002

Although there has been hereinabove described a specific methodapparatus for the treatment of dental and oral conditions, specificallyroot canals, in accordance with the present invention for the purpose ofillustrating the manner in which the invention may be used to advantage,it should be appreciated that the invention is not limited thereto. Thatis, the present invention may suitably comprise, consist of, or consistessentially of the recited elements. Further, the inventionillustratively disclosed herein suitably may be practiced in the absenceof any element which is not specifically disclosed herein. Accordingly,any and all modifications, variations or equivalent arrangements whichmay occur to those skilled in the art, should be considered to be withinthe scope of the present invention as defined in the appended claims.

1. A method of treating root canals, said method comprising: directingan oxidizing gas onto an open root canal through a needle; maintain apresence of the oxidizing gas onto the root canal for a period of timesufficient to kill microorganisms therein; and preventing escape of theoxidizing gas from the root canal.
 2. The method according to claim 1further comprising flushing the oxidizing gas from the root canal with areductant.
 3. Apparatus for the treatment of root canals, said apparatuscomprising: a source of oxidizing gas; a handpiece; a needle extendingfrom said handpiece and receivable in a tooth root canal, said needleincluding an oxidizing gas delivery lumen therethrough; a cup attachedto said handpiece and surrounding said needle; and a source of reductantinterconnected with said handpiece in order to flush the gas from saidcup.
 4. The apparatus according to claim 3 wherein said oxidizing gascomprises ozone.
 5. The apparatus according to claim 3 wherein saidneedle is flexible.
 6. The apparatus according to claim 3 wherein saidcup includes a resistant edge engagable with a cusp area of the tooth.7. The apparatus according to claim 3 wherein said source of oxidizinggas includes an ozone pump and further comprises an aspiration pump andan aspiration line connecting to said handpiece and circulating the gasthrough the needle lumen and out of a cusp chamber subtending a cupedge.
 8. The apparatus according to claim 7 wherein said aspiration lineis separate from said needle line.
 9. The apparatus according to claim 7further comprises an ozone and aspiration pump controller to circulatethe gas through the needle lumen and out of the cup chamber a pressureinsufficient to escape past a sealed engagement between the cup and thetooth.
 10. The apparatus according to claim 7 further comprising areductant pump for circulating the reductant through the needle line andcup to flush the oxidizing gas from the cup and into said aspirationline.
 11. The apparatus according to claim 7 further comprising a wastereductant accumulator connected to said aspiration line.
 12. Theapparatus according to claim 7 further comprising a residual oxidizinggas aspiration line filter.